1. Field of Endeavor
The present invention relates to protection of buildings and places and more particularly to protection of ventilation systems in places or buildings or vehicles.
2. State of Technology
High Efficiency Particulate Air (HEPA) filters are widely used commercial products. They “were originally developed as the particulate stage of a chemical, biological, radiological filtration/adsorber unit. In the late 1940s, the U.S. Atomic Energy Commission adopted them for use for the containment of airborne radioactive particulates in the exhaust ventilation systems of experimental reactors as well as for use in other phases of nuclear research. The period from the mid 1950s to the present has seen the emergence of many new industrial and scientific technologies requiring particulate free air in order to produce more sensitive products such as microelectronic components, photoproducts, drugs and dairy products. These technologies fostered the development of a wide range of specialized devices to house HEPA filters (and other types of similar filters) to deliver clean air to production areas. Uses for HEPA filters in hazardous containment applications have increased also, and they are more routinely used on the exhaust side of bio-hazard hoods, animal disease research laboratories and whenever airborne carcinogens must be controlled.”
Existing HEPA filters are made from glass and polymer fiber along with polymer binders, which are fragile and easily damaged due to effects of chemicals, high pressures and temperatures. A ceramic HEPA filter technology would overcome these problems and potentially would allow the filter to be cleaned and reused, thereby reducing secondary waste. The ceramic HEPA filter technology would be designed to minimize retrofit problems and costs while meeting several key HEPA filter requirements.
U.S. Pat. No. 6,787,104 to Raymond P. Mariella, Jr., assigned to The Regents of the University of California, filed Sep. 14, 2000, and issued Sep. 7, 2004 provides the following state of technology information.
“Biological agent weapons have been around at least since the Middle Ages when soldiers are reported to have catapulted the bodies of dead smallpox or plague victims over fortress walls in the hope of infecting their enemies or at least demoralizing them. Today, biological weapons (BW) are appearing in the news with increasing frequency. The anthrax threat in Las Vegas in February 1998 is an example. Surplus stores in Las Vegas sold out of gas masks, and talk-radio shows were swamped with callers asking about evacuation points. That threat turned out to be a false alarm, but the next one might be real. The Aum Shinrikyo cult grew and released anthrax spores in Tokyo, but, fortunately they did not have and effective means of dispersal of the spores and no deaths were reported. In Sverdlovisk, Union of Soviet Socialistic Republics in 1979 a quantity of dry anthrax spores were accidentally released from a military facility, killing 67 people downwind.”
“Biological agents are of concern in part because of the ease with which many of them can be manufactured, transported, and dispensed. Because of the lag time between a biological attack and the appearance of symptoms in those exposed, biological weapons could be devastating. Many biological agents are contagious; and during this lag time, infected persons could continue to spread the disease, further increasing its reach. Hundreds or even thousands of people could become sick or die if a biological attack were to occur in a major metropolitan area.”
“A historical example illustrates the scale of the effort required to respond to an act of BW terror in a major metropolitan area. In 1947, an American businessman traveled to New York City from Mexico City. During his bus ride, he developed a fever, headache, and rash. Though ill upon his arrival in New York, he went sightseeing. Over a period of several hours, he walked around the city and through a major department store. His illness, smallpox, progressed and he died nine days later. As a result of this single case, other cases of smallpox and two deaths occurred. Because of smallpox's ability to be transmitted from person to person, this handful of cases was deemed so serious by public health officials that 6,350,000 persons in New York City alone were vaccinated in less than a month.”
“In view of the foregoing, there is an increasing need for a system for detecting and eliminating biological and chemical agents. The system could be installed in a building or other area with an enclosed airspace. For example the system could be installed in subways, airports, entertainment centers, religious centers, office complexes, convention centers, and other sites where the public is at high risk of exposure to a covert release of biological or chemical agents. The system could also be part of a network of systems installed in urban areas or large events such as inaugurations or the Olympics.”
“The majority of detection and identification systems that are currently commercially available generally require a laboratory setting for testing and are designed for one positive detection only (Military System). There is also the question “what would be recommended as an action, if a real pathogen were detected?” Most people do not have a HEPA-filtered mask available. Even if a HEPA-filtered mask were available, it would likely not be properly fitted; and the individual would likely not be properly trained for its use.”